This invention relates to an adjustable gas tube assembly for gas consumption means, such as a burner element in a gas barbecue grill. More specifically, it relates to an adjustable gas tube assembly in which a tubular air regulator member having an elongated opening is selectively positioned within a gas delivery tube to expose predetermined portions of the lateral opening, as may be desired.
Gas delivery tubes, including venturi tubes, which deliver gas to a burner element in a barbecue grill have valves or regulators to regulate the amount of air drawn into the gas delivery tube by the flow of gas therethrough. The venturi delivery system of U.S. Pat. No. 3,638,635 includes a complex valve arrangement including fittings and valves which are connected to the venturi tube, to admit a predetermined amount of air into the system as desired More modern construction such as shown in U.S. Pat. No. 4,488,534 include the now well-known rotatable air regulator which is adjustably mounted over a venturi tube and is rotated, as desired, to selectively open a predetermined portion of a lateral opening provided in the venturi tube. While the aforementioned designs have worked quite well, with the increasing need to remain world-wide cost competitive, they are more unduly complex and are more costly than is required.
Additionally, it has been discovered that helically ribbed copper tubing with a thick polymeric coating, such as shown in U.S. Pat. Nos. 3,472,131, and 3,472,132, may be used as a flexible and expandable gas delivery tube. While it was thought that heat might adversely effect such constructions in the contemplated environment of the present invention, they have been found to be exceedingly safe and work quite well in the intended environment. With such flexible and expandable tubing available as the gas delivery tube, new opportunities also then existed to completely re-design the air regulator system. While the tubular air regulator member of the present invention works well in connection with flexible and expandable tubing of the type described above, it also can be used with other flexible and non-flexible gas delivery tube systems as well.